U.S. patent number 4,429,905 [Application Number 06/335,362] was granted by the patent office on 1984-02-07 for dual opposed seal ring coupling.
This patent grant is currently assigned to Stanley Aviation Corporation. Invention is credited to Gordon A. Valentine.
United States Patent |
4,429,905 |
Valentine |
February 7, 1984 |
Dual opposed seal ring coupling
Abstract
A fluid-conveying coupling assembly in which a pair of
torsionally deflectable seal rings establish a redundant seal
between interconnected coupling structures and in which the seal
rings are oriented and deflected in such a manner that they impose
non-cumulative radially directed forces on the interconnected
structures.
Inventors: |
Valentine; Gordon A. (Denver,
CO) |
Assignee: |
Stanley Aviation Corporation
(Denver, CO)
|
Family
ID: |
23311456 |
Appl.
No.: |
06/335,362 |
Filed: |
December 29, 1981 |
Current U.S.
Class: |
285/93; 285/331;
285/340; 285/363; 285/917 |
Current CPC
Class: |
F16L
23/0286 (20130101); F16L 23/167 (20130101); Y10S
285/917 (20130101) |
Current International
Class: |
F16L
23/028 (20060101); F16L 23/16 (20060101); F16L
23/00 (20060101); F16L 035/00 (); F16L 019/08 ();
F16L 023/00 () |
Field of
Search: |
;285/93,363,331,339,340,DIG.18 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Scanlan, Jr.; Richard J.
Attorney, Agent or Firm: LeBlanc, Nolan, Shur & Nies
Claims
What is claimed and desired to be secured by Letters Patent is:
1. In a coupling assembly, first and second tubular fluid
passage-defining structures, means for relatively drawing said
structures axially together to assemble said structures in coupled
relation to each other, said structures defining therebetween first
and second cavities each extending circumferentially around the
longitudinal axes of said structures, first and second seal rings
each received in a separate one of said cavities and each being
torsionally deflectable about its cross section to a condition in
which it establishes a substantially fluid tight seal between said
structures, and coacting means on said first and second structures
for engaging said seal rings and torsionally deflecting said seal
rings about their cross sections as said structures are drawn
axially together, said seal rings engaging said coacting means at
locations where they impose non-cumulative radially directed forces
on said structures upon being torsionally deflected to their
sealestablishing conditions.
2. The coupling assembly defined in claim 1 wherein said first
structure engages an outer peripheral region of only said first
seal ring and an inner peripheral region of only said second seal
ring, and wherein said second structure engages an outer peripheral
region of only said second seal ring and an inner peripheral region
of only said first seal ring.
3. The coupling assembly defined in claim 1 wherein each of said
structures is formed with a fluid flow passage to provide for the
flow of fluid through the assembly of said first and second
structures, wherein said cavities are disposed radially outwardly
of the fluid flow passages of said structures and circumferentially
surround said passages, and wherein said cavities are radially
spaced apart from each other and are axially overlapping.
4. The coupling assembly defined in any one of the preceding claims
1-3 wherein said coacting means comprises first, second, third and
fourth corners extending circumferentially around the longitudinal
axes of said structures, said first and second corners delimiting
said first cavity, and said third and fourth corners delimiting
said second cavity, said second and third corners being formed on
said first structure and said first and fourth corners being formed
on said second structure, said first seal ring being formed with a
pair of diagonally opposite corner edges, said structures engaging
said first seal ring at said corner edges of said first seal ring
as said structures are drawn axially together to seat said corner
edges of said first seal ring in said first and second corners to
effectuate the torsional deflection of said first seal ring for
compressively radially loading said first seal ring at said corner
edges of said first seal ring, said second seal ring being formed
with a pair of diagonally opposite corner edges, said structures
engaging said second seal ring at said corner edges of said second
seal ring to seat said corner edges of said second seal ring in
said third and fourth corners to effectuate the torsional
deflection of said second seal ring for compressively radially
loading said second seal ring at said corner edges of said second
seal ring.
5. The coupling assembly defined in any one of the preceding claims
1-3 wherein said coacting means comprises first, second, third and
fourth formations, said second and third formations being formed on
said first structure and said first and fourth formations being
formed on said second structure, said first and second formations
delimiting said first cavity and engaging said first seal ring to
torsionally deflect said first seal ring, and said third and fourth
formations delimiting said second cavity and engaging said second
seal ring to torsionally deflect said second seal ring.
6. The coupling assembly defined in claim 1 wherein each of said
structures is formed with a fluid flow passage, the fluid flow
passages of said structures opening into each other to provide for
the flow of fluid through the assembly of said first and second
structures, said second structure being formed with a recess
opening axially toward said first structure and having radially
spaced apart side walls, said recess being spaced radially
outwardly of and peripherally surrounding the fluid flow passage of
said second structure, said first structure being formed with a
portion extending axially into said recess and peripherally
surrounding the longitudinal axes of said structures, and said
coacting means comprising first, second, third and fourth
formations, said first formation forming a part of one of said side
walls, said fourth formation forming a part of the other of said
side walls, said second and third formations being formed on said
portion of said first structure, said first seal ring having a pair
of diagonally opposite corner edges, said first and second
formations delimiting said first cavity and engaging said corner
edges of said first seal ring as said structures are drawn axially
together to effectuate the torsional deflection of said first seal
ring about its cross section, said second seal ring being formed
with a pair of diagonally opposite corner edges, and said third and
fourth formations delimiting said second cavity and engaging said
diagonally opposite corner edges of said second seal ring as said
structures are drawn axially together to effectuate the torsional
deflection of said second seal ring about its cross section.
7. The coupling assembly defined in claim 6 wherein said first seal
ring is torsionally deflected in a pre-selected direction by said
first and second formations, and wherein said second seal ring is
torsionally deflected by said third and fourth formations in a
direction opposite to said pre-selected direction.
8. The coupling assembly defined in claim 7 wherein said seal rings
are radially spaced apart from each other, and wherein said portion
of said first structure extends between said seal rings.
9. The coupling assembly defined in claim 6 wherein said first seal
ring lies radially inwardly of said second seal ring to provide a
primary seal for preventing fluid in said fluid flow passages from
leaking outwardly along a path extending between said structures,
and wherein said second seal ring is disposed along said path to
provide a seal for blocking leakage of fluid past said first seal
ring.
10. The coupling assembly defined in claim 9 wherein said second
structure is formed with a further passage communicating with a
region of said recess which lies between said seal rings, there
being means connected to said further passage for detecting the
presence of gas leakage into said region of said recess.
11. In a coupling assembly, first and second tubular fluid flow
passage-defining structures, means for relatively drawing said
structures axially together to assemble said structures in coupled
relation to each other, said structures defining therebetween first
and second cavities each extending circumferentially around the
longitudinal axes of said structures, first and second seal rings
each received in a separate one of said cavities and each being
torsionally deflectable about its cross section to a condition in
which it establishes a substantially fluid tight seal between said
structures, said seal rings being serially arranged along a common
fluid leakage path which extends along the interface between said
structures such that the seal established by each of said seal
rings blocks leakage of fluid along said path, and coacting
formations on said first and second structures for torsionally
deflecting said seal rings in opposite directions about their cross
sections.
Description
FIELD OF INVENTION
This invention relates to fluid-conveying couplings and other
assemblies having a plurality of torsionally deflectable seal rings
for establishing a fluid-tight seal between the interconnected,
fluid-conveying parts. In particular, the present invention
constitutes an improvement over the dual seal ring arrangement
shown in FIG. 4 of U.S. Pat. No. 3,625,552 which issued to George
A. Mahoff on Dec. 7, 1971.
BACKGROUND
The dual seal ring arrangement in FIG. 4 of the Mahoff patent
advantageously provides a redundant seal whereby should one of the
seal rings fail, the other will maintain a seal between the
coupling members. Mahoff's redundant seal ring arrangement,
however, has the undesirable effect of reducing the interference
which is required between each seal ring and the coupling members
for establishing a tight seal.
In the Mahoff coupling, the seal rings are torsionally deflected to
their seal-establishing conditions by engaging the seal rings with
formations on the coupling members and by axially drawing the
coupling members together. Upon being torsionally deflected, each
seal ring will be deformed into a cone-shaped configuration in
which the seal ring's radial dimension is increased, thereby
creating the required interference or sealing pressure for
establishing the fluid-tight seal.
Because of the arrangement of the Mahoff seal rings with the
coupling members, the radial forces exerted by the seal rings on
each coupling member will be in the same direction. These seal
ring-exerted forces will therefore be cumulative and will have the
undesirable effect of radially deflecting the seal ring-engaging
portions of the coupling members away from each other to reduce the
tightness of the seal between the coupling members.
The effect of the cumulative radial forces on the coupling members
in the Mahoff coupling is normally not a significant problem in
small couplings because of the relatively high radial stiffness of
the coupling members. However, in large couplings having tube sizes
greater than three inches, the radial stiffness of the coupling
members is reduced to such an extent that it is insufficient to
prevent the coupling members from being radially deflected to a
substantial degree under the influence of the cumulative seal
ring-exerted forces. For large coupling sizes, the sealing pressure
is therefore reduced to a level that is often too low for
establishing a satisfactory seal.
The present invention overcomes the foregoing problem but retains
the advantage of the dual seal ring redundancy.
SUMMARY AND OBJECTS OF INVENTION
In the redundant seal ring coupling of this invention, the two seal
rings exert non-cumulative radial forces on the coupling members,
rather than cumulative forces, with the result that a higher degree
of sealing pressure is established as compared with the Mahoff dual
seal ring coupling. This is accomplished by an arrangement in which
one coupling member engages an outer peripheral corner edge of a
first seal ring and an inner peripheral corner edge of a second
seal ring and in which the other coupling member engages an inner
peripheral corner edge of the first seal ring and an outer
peripheral corner edge of the second seal ring. The arrangement is
such that the two seal rings will be torsionally deflected in
opposite directions as the coupling members are drawn axially
together. With this unique arrangement, the radial forces exerted
by the seal rings on each coupling member will be oppositely acting
and therefore non-cumulative.
In the comparison to the present invention, Mahoff's dual seal ring
coupling is constructed in such a way that one coupling member
engages outer corner edges of both seal rings while the other
coupling member engages inner corner edges of both seal rings to
torsionally deflect both seal rings in a common direction and to
create a force pattern in which the radial forces imposed on each
coupling member cumulatively act in a common direction.
With the foregoing in mind, the general aim and purpose of the
present invention is to provide a novel redundant seal ring
coupling assembly which overcomes the previously described problem
of the Mahoff seal ring assembly.
A more specific object of this invention is to provide a novel dual
torsionally deflectable seal ring coupling assembly wherein
non-cumulative radially directed forces are exerted by the seal
rings on the coupling members or other structures.
Further objects of this invention will appear as the description
proceeds in connection with the below-described drawings and the
appended claims.
DESCRIPTION OF DRAWINGS
FIG. 1 is an end view of a coupling assembly incorporating the
principles of this invention;
FIG. 2 is a plan view of the coupling assembly shown in FIG. 1;
FIG. 3 is a section taken substantially along lines 3--3 of FIG.
1;
FIG. 4 is an enlarged fragmentary view of the sectioned coupling
shown in FIG. 3 to illustrate the dual opposed seal ring assembly
in greater detail; and
FIG. 5 is a sectioned fragmentary view similar to FIG. 4 but
showing the coupling assembly in partially assembled form where the
seal rings are still in their relaxed, undeflected conditions.
DETAILED DESCRIPTION
Referring to FIGS. 1-3 of the drawings, the coupling assembly
incorporating the principles of this invention is used to couple
together a pair of tubular fluid-conveying pipes or conduits 10 and
12 and mainly comprises a pair of axially aligned coupling members
or flanges 14 and 16, a coupler ring 18, and a pair of torsionally
deflectable seal rings 20 and 22. Flange 14 is welded or otherwise
suitably fixed to conduit 10, and flange 16 is similarly welded or
otherwise suitably fixed to conduit 12. Flanges 14 and 16 axially
confront each other and are detachably coupled together by coupler
ring 18 and a multiplicity of angularly spaced apart bolts 24.
In the illustrated embodiment, coupling flanges 14 and 16 are
annular and are formed with uniformly diametered through passages
25 and 27, respectively, to establish fluid communication between
pipes 10 and 12. It will be appreciated, however, that the coupling
flanges, seal rings and coupler ring may alternatively be
rectangular or some other non-circular shape.
Coupler ring 18 coaxially and peripherally surrounds a radially
extending portion 26 of flange 14 and is formed with a radially
inwardly extending lip 28 which seats against the side of flange
portion 26 which faces axially away from flange 16. Bolts 24 extend
through parallel, smooth walled bores 30 in ring 18 and are
threaded into tapped bores 32 in a radially extending portion 34 of
flange 16. Flange 14 is clamped and axially confined between the
coupler ring's lip portion 28 and an opposing end face 36 of flange
16.
As best shown in FIGS. 3 and 4, each of the seal rings 20 and 22 is
of the same construction as that disclosed in the previously
identified Mahoff U.S. Pat. No. 3,625,552. Seal ring 20 is thus
formed with a rectangular cross section to define a pair of
circumferentially extending, diagonally opposite corner edges 40
and 41, and seal ring 22 is likewise formed with a rectangular
cross section to also define a pair of circumferentially extending
diagonally opposite corner edges 42 and 43. The disclosure of the
Mahoff U.S. Pat. No. 3,625,552 is hereby incorporated into this
specification by reference. As disclosed in the Mahoff patent, each
of the torsionally deflectable seal rings is formed from a suitable
metal which is resilient and preferably somewhat ductile. In the
illustrated embodiment, seal rings 20 and 22 have different
diameters, are concentrically arranged and are radially spaced
apart from each other.
As best shown in FIG. 3, coupling flange 14 is formed with an
annular, flat, radially extending end face 46 which confronts and
overlaps with the end face 36 of coupling flange 16. Coupling
flange 16, which may be considered as the female coupling member in
the illustrated embodiment, is formed with a generally annular
recess or groove 50 which coaxially surrounds the flange's
fluid-conveying passage 27 and which opens towards flange 14 at the
flange's end face 36. Coupling flange 14, which may be considered
as the male coupling member in the illustrated embodiment, is
integrally formed with an annular lip 52 which is coaxial with the
flanges' flow passages 25 and 27 and which protrudes axially beyond
end face 46 and into recess 50. Lip portion 52 is integrally joined
to flange portion 26 by an intermediate circumferentially extending
portion 54 which has a conical configuration in cross section. The
conically contoured portion 54 is received in the mouth of recess
50 and coaxially surrounds the aligned longitudinal axes of flanges
14 and 16. The lip and intermediate portions 52 and 54 are spaced
radially outwardly from flow passage 25.
As best shown in FIG. 4, lip portion 52 is formed with inner and
outer oppositely facing, smooth, uniformly diametered, cylindrical
peripheral surfaces 56 and 57. Portion 54 is formed with inner and
outer endless circumferentially extending conically contoured
surfaces 58 and 59, each lying in a conical envelope. In cross
section, the conically contoured surfaces 58 and 59 are oppositely
sloped so that the conical envelopes containing these surfaces are
oppositely facing and have their apexes lying along the
longitudinal axis of coupling flange 14.
The cylindrical surface 56 is contiguous with and intersects the
conically contoured surface 58 at an obtuse angle to form a
circumferentially extending corner 60 for receiving the outer
corner edge 41 of seal ring 20. Cylindrical surfaces 57 is
contiguous with and intersects the conically contoured surface 59
at an obtuse angle to form another circumferentially extending
corner 61 for receiving the inner circumferentially extending
corner 42 of seal ring 22. Corners 60 and 61 are oppositely
facing.
Cylindrical surface 56 thus cooperates with the conically contoured
surface 58 to define an outer circumferentially extending formation
62 for engaging seal ring 20. Formation 62 cooperates with an inner
circumferentially extending formation 63 (to be described in detail
later) for torsionally deflecting seal ring 20 to its
seal-establishing condition.
The cylindrical surface 57 and the conically contoured surface 59
coact to define a further circumferentially extending formation 64
for engaging seal ring 22. Formation 64 cooperates with another
circumferentially extending seal ring engaging formation 65 (to be
described later) for torsionally deflecting seal ring 22 to its
seal-establishing condition.
As best shown in FIG. 4, the seal ring-engaging formations 63 and
65 are integrally formed on coupling flange 16. Formation 63 is
formed at the mouth of recess 50 and defines the outer portion of
the recess' inner side wall 68. Formation 65, which is also formed
at the mouth of recess 50, lies in opposing relationship to
formation 63 and defines the outer portion of the recess' outer
side wall 70. By virtue of the configurations of formations 63 and
65, the mouth of recess 50 is outwardly flared as shown.
Still referring to FIG. 4, the seal ring-engaging formation 63 is
defined by a pair of contiguous, circumferentially extending,
conically contoured surfaces 72 and 73 which are provided with
different slopes and which intersect with each other at an obtuse
angle to define a further circumferentially extending corner 74 for
receiving the inner circumferentially extending corner edge 40 of
seal ring 20. As shown, surfaces 72 and 73 are contained in
separate conical envelopes having their apexes lying along the
longitudinal axis of coupling flange 16.
Similar to formation 63, formation 65 is also defined by a pair of
contiguous, conically contoured, circumferentially extending
surfaces 76 and 77 which are provided with different slopes and
which intersect with each other to define a further
circumferentially extending corner 78 for receiving the outer
circumferentially extending corner edge 43 of seal ring 22.
Surfaces 76 and 77 are contained in separate conical envelopes
having their apexes lying along the longitudinal axis of coupling
flange 16.
Corners 60 and 74 open diagonally toward each other. Likewise,
corners 61 and 78 open diagonally toward each other.
Still referring to FIG. 4, the lip portion 52 of coupling flange 14
is centrally received in recess 50 so that it lies midway between
the recess' side wall 68 and 70 and therefore is equally spaced
from side wall 68 and 70. In the assembled position of parts shown
in FIGS. 3 and 4, formations 62 and 63 cooperate with each other to
define a circumferentially extending cavity 80 which receives seal
ring 20. Similarly, formations 64 and 65 cooperate to define
another circumferentially extending cavity 82 which receives seal
ring 22.
Cavities 80 and 82 are radially spaced apart from each other and
are concentrically arranged. Cavities 80 and 82 are coaxial with
the aligned axes of coupling flanges 14 and 16.
In the fully assembled, seal-establishing arrangement of parts as
shown in FIGS. 3 and 4, lip portion 52 extends coaxially between
seal rings 20 and 22 such that seal ring 20 is disposed on the
inner peripheral side of lip portion 52 while seal ring 22 is
disposed on the outer peripheral side of lip portion 52. In the
seal-establishing assembly of parts shown in FIGS. 3 and 4, the
diagonally opposite corner edges 40 and 41 of seal ring 20 are
seated in corners 74 and 60, respectively, and the diagonally
opposite corner edges 42 and 43 of seal ring 22 are seated in
corners 61 and 78, respectively.
For assembling the parts of the coupling assembly and establishing
the fluid tight seal with seal rings 20 and 22, coupling flanges 14
and 16 are axially aligned at positions shown in FIG. 5 where their
end faces 46 and 36 confront each other and where the annular lip
52 registers or aligns with recess 50 and extends between seal
rings 20 and 22 which are in their relaxed, undeflected conditions
in the mouth of recess 50. Coupling ring 18 is assembled on
coupling flange 14 to engage the backside of coupling flange 14,
and bolts 24 are tightened to axially draw coupling flanges 14 and
16 together. In their relaxed, undeflected conditions as shown in
FIG. 5, the cross sections of seal rings 20 and 22 will each have
an undistorted rectangular configuration. Furthermore, the flat,
oppositely facing end faces of each of the seal rings 20 and 22
will lie in parallel planes when the seal ring is in its
undeflected condition as shown in FIG. 5.
As the coupling flanges 14 and 16 are axially drawn together from
the positions of parts shown in FIG. 5, formations 62 and 63 will
both engage seal ring 20 and, at the same time, formations 64 and
65 will both engage seal ring 22. Engagement of seal ring 20 with
formations 62 and 63 applies a force couple to seal ring 20 to
initiate the torsional deflection of seal ring 20 and to urge seal
ring 20 into a position where its diagonally opposite corner edges
40 and 41 seat in corners 74 and 60, respectively. Likewise,
engagement of seal ring 22 with formations 64 and 65 applies a
force couple to seal ring 22 to initiate the torsional deflection
of seal ring 22 and to urge seal ring 22 into a position where its
diagonally opposite corner edges 42 and 43 seat in corners 61 and
78, respectively. Thereafter, continued relative axial displacement
of coupling flanges 14 and 16 toward each other fully torsionally
deflects seal rings 20 and 22 to their sealestablishing condition
shown in FIG. 4. Axial displacement of coupling flanges 14 and 16
toward each other is limited by seating engagement of the flange
end face 46 with the flange end face 36.
Upon being fully torsionally deflected in the manner shown in FIG.
4, each of the seal rings 20 and 22 will be deformed to a
cone-shaped configuration in which the radial dimension of each
seal ring is increased to cause the interference that produces the
fluid tight seal between coupling flanges 14 and 16. It will be
appreciated that the torsional deflection of each of the seal rings
20 and 22 is brought about by the force couple mentioned above
which effectively pivots or rotates the seal ring's cross section
about a center lying on the cross section. Seal ring 20 will
therefore be radially, compressively loaded at its diagonally
opposite corner edges 40 and 41, and seal ring 22 will likewise be
radially, compressively loaded at its diagonally opposite corner
edges 42, 43.
In the torsionally deflected condition of seal ring 20 as shown in
FIG. 4, a first sealing interface is established at the line of
contact between the seal ring's corner edge 40 and corner 74, and a
second sealing interface is established at the line of contact
between the seal ring's corner edge 41 and corner 60. In its
torsionally deflected condition shown in FIG. 4, seal ring 22 also
establishes two sealing interfaces, one being established at the
line of contact between corner edge 42 and corner 61, and the other
being established at the line of contact between corner edge 43 and
corner 78.
In FIG. 4, it will be observed that seal ring 20 engages formations
63 and 62 only at corners 74 and 60. Similarly, seal ring 22
engages formations 64 and 65 only at corners 61 and 78. Depending
upon the dimensions of the component parts in the coupling
assembly, each of the seal rings 20 and 22 may be torsionally
deflected to a further extent where its oppositely directed end
faces seat against the opposing conically contoured surfaces of its
associated seal ring-engaging formations as shown, for example, in
FIG. 3 of the Mahoff patent, but such additional torsional
deflection of the seal ring is unnecessary for establishing the
fluid tight seal between coupling flanges 14 and 16.
From FIG. 3 it will be observed that a first radially extending
plane normally intersecting the aligned axes of coupling flanges 14
and 16 passes through the seal ring-engaging corners 60 and 61 and
hence through the engaged corner edges 41 and 42 of seal rings 20
and 22, respectively. Similarly, a second radially extending plane
normally intersecting the aligned axes of coupling flanges 14 and
16 and extending parallel to the first plane mentioned above passes
through the seal ring-engaging corners 74 and 78 and hence through
the corner edges 40 and 43 of seal rings 20 and 22,
respectively.
From the description thus far, it will be appreciated that seal
rings 20 and 22 will be torsionally deflected about their cross
sections in opposite directions. It also will be appreciated that
each of the coupling flanges 14 and 16 is engaged by the outer
periphery of only one of the seal rings and further that each of
the coupling flanges is engaged by the inner periphery of only one
of the seal rings. This unique arrangement creates a force pattern
in which the torsionally deflected seal rings apply non-cumulative,
opposite radial forces to each of the coupling flanges 14 and 16.
In the case of coupling flange 14 the radial forces are
counterbalancing. In the case of coupling flange 16 the radial
forces act away from each other tending to spread the mouth of
recess 50, but these radially directed forces will be reacted
locally in the confined region of recess 50 and over a relatively
short radial distance extending between corners 74 and 78 where
coupling flange 16 is relatively stiff to thus adequately resist
the radial deflection of formations 63 and 65 away from each other.
The sealing pressure or interference required for establishing a
tight seal therefore will not be impaired notwithstanding the use
of two rings to achieve a redundant sealing action.
It will be observed that seal rings 20 and 22 are serially spaced
apart along the fluid leak path which extends along the interface
between coupling flanges 14 and 16. Seal ring 20 acts as the
primary seal while seal ring 22 acts as a backup to provide the
redundant sealing action in which seal ring 22 tends to block any
leakage past seal ring 20 and operates as the primary seal if seal
ring 20 fails.
In the illustrated embodiment, a bore 90 is formed through the
radially extending portion 34 of flange 16 and opens into recess 50
at a region lying between seal rings 20 and 22. A detector 92 is
optionally connected to bore 90 and may be of any suitable type for
detecting fluid in the region of recess 50 which lies between seal
rings 20 and 22 to thus detect leakage past seal ring 20. Detector
92, for example, may be a simple sensor for sensing the presence of
gas. Alternatively, it may be a pressure indicating device for
monitoring the pressure in recess 50.
In the illustrated embodiment a plurality of washers 94 are
optionally fixed to the flat end face of lip portion 52 by screws
96. Washers 94 are equiangularly spaced apart and serve as guides
for seal rings 20 and 22 during assembly of the coupling flanges.
Washers 94 also serve to engage and forcibly dislodge seal rings 20
and 22 from coupling flange 16 upon disconnecting the coupling
flanges.
Reference to the coupling flanges or other fluid-conveying
structures as being "tubular" is intended to cover both circular
and non-circular (e.g., rectangular) configurations.
The invention may be embodied in other specific forms without
departing from the spirit or essential characteristics thereof. The
present embodiment is therefore to be considered in all respects as
illustrative and not restrictive, the scope of the invention
indicated by the appended claims rather than by the foregoing
description, and all changes which come within the meaning and
range of equivalency of the claims are therefore intended to be
embraced therein.
* * * * *